In recent years, it has been found that there are many organic compounds produced in nature that are as yet completely unknown to man. Researchers in various fields have an interest in isolating and characterizing such compounds and determining whether they have utility in particular areas of interest.
One particularly rich source of organic compounds of this type is the roots of plants. Both herbaceous and woody plants generate organic compounds in their roots. These compounds, often referred to as bioactive phytochemicals, perform a number of functions on behalf of the plant. These functions are primarily protective of the plant against threats such as, inter alia, bacteria, fungi, other plants and insects. The nature of the chemicals produced by a particular plant reflects not only the identity of the plant, but, to a great degree, the environment to which that plant is adapted.
In the natural functioning of the plant, bioactive phytochemicals are contained both within the body of the root and in a mucilaginous sheath formed about the exterior of the root. The nature of the mucilaginous sheath is not completely known, but is believed to be made up of hydrated polysaccharides and mucopolysaccharides. In fact, the great significance of the mucilaginous sheath with respect to the functioning of the bioactive phytochemicals has only recently been realized.
Interest in such compounds is particularly strong in the pharmaceuticals field. Pharmaceutical researchers are especially interested, not only for the possible pharmaceutical activity of such compounds per se, but also for their possible utility as lead compounds for derivatization into other pharmacologically active forms. A substantial amount of effort has been applied to finding and recovering these organic compounds from nature for study.
Presently practiced techniques for recovering organic compounds from plant roots generally involve removing the roots from the remainder of the plant, reducing the roots to a smaller particle size and subjecting the small particle residue to a standard extraction process using conventional organic solvents. This technique, although it is effective in recovering the desired materials, has several drawbacks.
One serious drawback of currently practiced techniques is that the plant is completely destroyed in the process. This is an economic drawback since it now becomes necessary to replace the plant, which can only be done by growing another plant--a time-consuming and sometimes uncertain undertaking. Further, some of the plants that are used are somewhat rare and it is environmentally undesirable for them to be destroyed.
Another drawback of the current process is that, since the process involves solvent extraction, it may be necessary to employ more than one solvent in order to extract all the species present in a candidate plant root system. This can be a problem if the solvents being used are not compatible or if they otherwise require the extraction process to be carried out in more than one step.
It is the object of this invention to provide a novel and improved technique for separating organic compounds from the roots of plants. It is a particular objective of the invention to provide a technique for separating organic compounds from the roots and from the mucilaginous sheath associated with the roots of plants without destroying the plant from which the compounds are removed.
In accordance with this invention, it has been found that when a plant root system with the mucilaginous sheath surrounding the said root system intact or substantially intact, is placed in an aqueous medium containing an enzyme or a mixture of enzymes, the mucilaginous sheath is attacked by the enzyme(s) and the organic compounds within the sheath are liberated into the aqueous medium.